The functional properties of food proteins are closely related to their conformational state. In this research project, we investigated the mechanisms for the conformational changes in food proteins, using egg white proteins (ovalbumin and ovotransferrin) and serum albumin as model proteins.1.The X-ray crystallographic structure of both the iron-bound form of ovotransferrin was determined at 2.4 A resolution. It was found that the conformation of the protein is induced into a much more compact form by the iron-bindings.2.The disulfide-reduced forms of ovotransferrin and serum albumin were produced by incubation with dithiothreitol and their conformational characteristics were analyzed by the circular dichroism and intrinsic tryptophan fluorescence spectra. These protein forms were found to assume the molten globule like conformation.3.Both ovotransferrin and serum albumin were found to form opaque gels by their disulfide reduction. It was therefore concluded that the molten globule state is involved in the gelation process as crucial conformational states of these proteins.